Traditional approaches to synchronization in Modeling and Simulation (M & S) are time-stepped or discrete event-based. These conservative techniques can impose serious penalties in runtime and in opportunity cost where very expensive hardware spends valuable time waiting on results from other processing nodes. The Missile Defense Agency"s M & S Directorate (MDA/DES) advocates use of optimistic methods where speedier components can"work ahead,"but this approach requires programmers to write complex rollback logic that can result in difficult bugs. The team of deciBel Research and Galois combines successful track records in missile-defense modeling and cutting-edge research in computer science. In Phase I, the team will demonstrate an Optimistic Software Development Kit (OSDK) proof of concept by converting from discrete-event to optimistic a portion of deciBel Research"s existing dBTools radar-simulation suite. In Phase II, the team will develop a more general TimeWarp-based OSDK and use it to integrate the full dBTools suite into MDA"s Optimistic Modeling Framework (OMF).